Breathing assistance apparatus

ABSTRACT

Headgear for use with a respiratory mask is described. The headgear comprises a continuous and substantially curved elongate member extending in use below a user&#39;s nose and at least two headgear straps capable of attachment to the ends of the elongate member. A mask attachment on the elongate member is disposed to sit below or on one of said user&#39;s nose, mouth, upper lip and an inlet to the mask. The attachment is capable of receiving the mask.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

This application is a continuation application of U.S. patentapplication Ser. No. 12/633,135, filed Dec. 8, 2009, which is acontinuation application of U.S. patent application Ser. No. 12/307,993filed on Jun. 17, 2009, which is a 371 filing of PCT/NZ2007/000185 filedon Jul. 13, 2007 and published in English as WO 2008/007985 on Jan. 17,2008, which claims priority from New Zealand Application No. 548575filed on Jul. 14, 2006 and New Zealand Application No. 551103 filed onNov. 6, 2006. All of these applications are hereby incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to apparatus for treating sleep apnea.More specifically, the present invention provides a nasal interface forthe supply of respiratory gases, but most particularly positive pressuregases.

Description of the Related Art

In the art of respiration devices, a variety of respiratory masks whichcover the nose and/or mouth of a human user in order to provide acontinuous seal around the nasal and/or oral areas of the face are wellknown. Masks that provide gas at positive pressure within the mask forconsumption by the user are also well known. The uses for such masksrange from high altitude breathing (i.e., aviation applications) tomining and fire fighting applications, to various medical diagnostic andtherapeutic applications.

Obstructive Sleep Apnea (OSA) is a sleep disorder that affects up to atleast 5% of the population in which muscles that normally hold theairway open relax and ultimately collapse, sealing the airway. The sleeppattern of an OSA sufferer is characterised by repeated sequences ofsnoring, breathing difficulty, lack of breathing, waking with a startand then returning to sleep. Often the sufferer is unaware of thispattern occurring. Sufferers of OSA usually experience daytimedrowsiness and irritability due to a lack of good continuous sleep.

In an effort to treat OSA sufferers, a technique known as ContinuousPositive Airway Pressure (CPAP) was devised. A CPAP device consists of agases supply (or blower) with a conduit connected to supply pressurisedgases to a patient, usually through a nasal mask. The pressurised airsupplied to the patient effectively assists the muscles to keep thepatient's airway open, eliminating the typical OSA sleep pattern.

The procedure for administering CPAP treatment has been well documentedin both the technical and patent literature. Briefly stated, CPAPtreatment acts as a pneumatic splint of the airway by the provision of apositive pressure, usually in the range 4 to 20 cm H.sub.2O. The air issupplied to the airway by a motor driven blower whose outlet passes viaan air delivery hose to a nose, full face, nose and mouth, or oral maskthat is sealingly engaged to a patient's face, preferably by means of aharness or other headgear. An exhaust port is usually also provided inthe delivery tube proximate to the mask or on the mask itself. Moresophisticated forms of positive airway pressure devices, such asbi-level devices and auto-titrating devices, are described in U.S. Pat.No. 5,148,802 of Respironics, Inc. and U.S. Pat. No. 5,245,995 ofRescare Limited, respectively.

One requisite of respiratory masks has been that they provide aneffective seal against the user's face to prevent leakage of the gasbeing supplied. Commonly, in prior mask configurations, a goodmask-to-face seal has been attained in many instances only withconsiderable discomfort for the user. A common complaint of a user ofCPAP therapy is pressure sores caused by the mask about the nose andface and in particular in the nasal bridge region of the user. Thisproblem is most crucial in those applications, especially medicalapplications, which require the user to wear such a mask continuouslyfor hours or perhaps even days. In such situations, the user will nottolerate the mask for long durations and optimum therapeutic ordiagnostic objectives thus will not be achieved, or will be achievedwith great difficulty and considerable user discomfort.

U.S. Pat. No. 5,477,852 of Airways Ltd, Inc. discloses a nasal positiveairway pressure device that has a pair of nasal members each having acannula tip to be inserted into the nares of the patient. Each cannulais tapered from a substantially circular cross section outside thepatient's nostril to a substantially oval cross section at the tipinserted into the nostril. An inflatable cuff surrounds each cannulawith the interior space of the cuff communicating with the lumen of thecannula through at least one aperture in the sidewall of the cannula.The nasal members are connected to one or more flexible hoses that; inturn, are connected to a source of positive air pressure. In use,positive air pressure is supplied to each cannula tip through the airhoses and nasal members. The positive air pressure inflates the cuffs tohold the nasal members in place and to effect treatment. The nasaldevice of U.S. Pat. No. 5,477,852 is attached to headgear that islocated about a patient's head. This headgear could be considered bymany patients as cumbersome and uncomfortable.

Conventional nasal masks used for administrating CPAP treatment are alsoconsidered uncomfortable and cumbersome, and prior art nasal masks canbe noisy due to air leaks. These disadvantages in many cases are aformidable obstacle to patient acceptance of such treatment. Therefore,a substantial number of patients either cannot tolerate treatment orchoose to forego treatment. It is believed a number of such patientsmight benefit from a nasal positive airway pressure apparatus that ismore convenient to use and comfortable to wear, thereby resulting inincreased treatment compliance.

Innomed Technologies, Inc. manufactures a nasal cannula device calledthe NASALAIRE™. In this device air or oxygen travels down a wide boreconduit to nasal cannula. The NASALAIRE™ creates a physical seal betweenthe flares and itself, and relies on the absence of leaks around thecannula and the nares to deliver pressure supplied by a continuouspositive airway pressure (CPAP) blower to the airway of the wearer.

U.S. Pat. No. 6,119,694 of Respironics Ga., Inc discloses a nasal maskhaving a nare seal and lateral support members to support the mask.

WO2004/073778 of ResMed Limited discloses a nasal mask including a framewhere headgear is provided with rigid sections that extend to the nasalmask.

WO04/041341 of ResMed Limited discloses headgear for a patient mask thatincludes a sewn on rigid section to the back area of headgear straps toprovide rigidity to the straps.

U.S. Pat. No. 6,907,882 of ResMed Limited discloses a nasal mask andheadgear that is attachable to the frame of the nasal mask. The headgearstraps have rigid sections integral with the releasable connectors thatattach the headgear to the mask.

SUMMARY OF THE INVENTION

It is an object of the present invention to attempt to provide a patientinterface that goes some way to overcoming the abovementioneddisadvantages in the prior art or which will at least provide theindustry with a useful choice.

In a first aspect the present invention consists in headgear for usewith a respiratory mask comprising:

a continuous and substantially curved elongate member extending in usebelow a patient's nose,

at least two headgear straps capable of attachment to the ends of saidelongate member, and

a mask attachment on said elongate member disposed to sit below or onone of said user's nose, mouth, upper lip and an inlet to the mask, saidattachment capable of receiving said mask.

In a second aspect the present invention consists in a breathingassistance apparatus for use with delivery of respiratory gases to auser comprising:

a mask having a base and body, said body having two flexible nasalpillows that in use rest in a substantially sealed manner against saiduser's nares,

a continuous and substantially curved elongate member extending in usebelow a patient's nose,

at least two headgear straps capable of attachment to the ends of saidelongate member, and

a mask attachment on said elongate member disposed below said user'snose, said attachment capable of receiving said mask.

In a third aspect the present invention consists in a breathingassistance apparatus for use with delivery of respiratory gases to auser comprising:

a mask comprising a body and a cushion, said cushion substantiallyforming a seal with said patient's airways,

headgear comprising substantially flexible, soft straps and asubstantially continuous curved elongate member to which said mask isattached, said elongate member extending over said user's cheeks, and

wherein said mask has an inlet extension tube and said curved elongatemember is attached or rests beneath said inlet extension tube, anchoringsaid mask to said user's face in use.

To those skilled in the art to which the invention relates, many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the scope ofthe invention as defined in the appended claims. The disclosures and thedescriptions herein are purely illustrative and are not intended to bein any sense limiting.

In this specification where reference has been made to patentspecifications, other external documents, or other sources ofinformation, this is generally for the purpose of providing a contextfor discussing the features of the invention. Unless specifically statedotherwise, reference to such external documents is not to be construedas an admission that such documents, or such sources of information, inany jurisdiction, are prior art, or form part of the common generalknowledge in the art.

The invention consists in the foregoing and also envisages constructionsof which the following gives examples.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred forms of the present invention will now be described withreference to the accompanying drawings.

FIG. 1 is a block diagram of a humidified continuous positive airwaypressure system as might be used in conjunction with the nasal mask ofthe present invention.

FIG. 2 is a perspective view of a first form of a patient interface thatis nasal mask and headgear of the present invention.

FIG. 3 is an exploded view of the nasal mask and headgear of FIG. 2.

FIG. 4 is a side view of a mask base of the nasal mask and headgear ofFIG. 2.

FIG. 5 is a perspective end view of the mask base of FIG. 4.

FIG. 6 is an end view of a body of the nasal mask and headgear of FIG.2, particularly showing two nasal pillows.

FIG. 7 is a perspective view of the body of FIG. 6,

FIG. 8 is a perspective view of a nasal mask of the first form of thepresent invention but having alternative headgear that includesadditional rigid extensions.

FIG. 9 is perspective view of a second form of a patient interface andheadgear of the present invention.

FIG. 10 is an exploded view of the patient interface and headgear ofFIG. 9.

FIG. 11 is an exploded view of a third form of a patient interface andheadgear of the present invention.

FIG. 12 is an exploded view of a fourth form of a patient interface andheadgear of the present invention.

FIG. 13 is a perspective view of a fifth form of a patient interface andheadgear of the present invention.

FIG. 14 is an exploded view of the patient interface and headgear ofFIG. 13.

FIG. 15 is a perspective view of a sixth form of a patient interface andheadgear of the present invention.

FIG. 16 is a perspective view of a seventh form of a patient interfaceand headgear of the present invention.

FIG. 17 is a cross-sectional view of the patient interface of FIG. 16.

FIG. 18 is a front view of a nasal pillow of FIG. 6.

FIG. 19a is a front view of the nasal pillows of FIG. 6.

FIGS. 19b to 19d are graphs of the gradients of various nasal pillowconnecting surfaces.

FIG. 20 is a perspective view of an eighth form of a patient interfaceand headgear of the present invention.

FIG. 21 is a perspective view of the interface and headgear of FIG. 20showing inner pads on the arms of the headgear.

FIG. 22 is an exploded view of the interface and headgear of FIG. 20.

FIG. 23 is a perspective view of a ninth form of a patient interface andheadgear the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The breathing assistance apparatus of the present invention includingmasks and headgear as described in the preferred embodiments of thisinvention can be used in respiratory care generally or with aventilator. It is described below with reference to use in a humidifiedCPAP system.

A humidified Continuous Positive Airway Pressure (CPAP) system is shownin FIG. 1. A patient 1 is receiving humidified and pressurised gasesthrough a patient interface 2 connected to a humidified gasestransportation pathway or inspiratory conduit 3. Alternative deliverysystems may also be used such as, VPAP (Variable Positive AirwayPressure) and BiPAP (Bi-level Positive Airway Pressure) or numerousother forms of respiratory therapy. A nasal mask 2 is illustrated inFIG. 7 but other masks such as oral, full face or nasal cannula may beused.

An inspiratory conduit 3 is connected to an outlet 4 of a humidificationchamber 5 that contains a volume of water 6. The inspiratory conduit 3may contain heating means or heater wires (not shown) that heat thewalls of the conduit to reduce condensation of humidified gases withinthe conduit 3.

The humidification chamber 5 is preferably formed from a plasticsmaterial and preferably has a highly heat conductive base (for examplean aluminium base) that is in direct contact with a heater plate 7 ofhumidifier 8. The humidifier 8 is provided with control means or anelectronic controller 9 that may comprise a microprocessor basedcontroller executing computer software commands stored in associatedmemory.

The controller 9 preferably receives input from sources such as userinput means or a dial 10 through which a user of the device may, forexample, set a predetermined required value (preset value) of humidityor temperature of the gases supplied to patient 1. The controller 9 mayalso receive input from other sources, for example temperature and/orflow velocity sensors 11, 12, through a connector 13 and a heater platetemperature sensor 14. In response to the user set humidity ortemperature value input via the dial 10 and the other inputs, thecontroller 9 determines when (or to what level) to energise the heaterplate 7 to heat the water 6 within the humidification chamber 5. As thevolume of the water 6 within the humidification chamber 5 is heated,water vapour begins to fill the volume of the chamber above the water'ssurface and is passed out of the humidification chamber 5 outlet 4 withthe flow of gases (for example air) provided from a gases supply meansor blower 15 that enters the chamber 5 through an inlet 16. Exhaledgases from the patient's mouth are passed directly to the ambientsurroundings in FIG. 1.

The blower 15 is provided with variable pressure regulating means orvariable speed fan 21 that draws air or other gases through a blowerinlet 17. The speed of the variable speed fan 21 is controlled by anelectronic controller 18 (or alternatively the function of thecontroller 18 may be carried out by the controller 9) in response toinputs from the controller 9 and a user set predetermined required value(preset value) of pressure or the fan speed via dial 19.

FIGS. 2 and 3 show a first embodiment of a patient interface of thepresent invention. This patient interface is a nasal mask 2. The nasalmask 2 is comprised of a mask base 22 and body 23. The body 23 issubstantially tubular with two nasal pillows 24, extending from it. Thenasal pillows 24, 25 are preferably frustoconical in shape and in userest against a patient's nares, to substantially seal the patient'snares. The body 23 has an external lip 28 that frictionally fits in achannel in the mask base 22.

The body 23 and nasal pillows 24, 25 of the nasal mask of the presentinvention are shown in further detail in FIGS. 6 and 7. The body andpillows are preferably integrally moulded in a substantially flexibleplastics material. In the preferred form this material is silicone, butother appropriate materials, such as, rubber, thermoset elastomer orthermoplastic elastomer, such as Kraton™ may be used.

The nasal pillows 24, 25 are preferably an elliptical cone and as suchare tubular and allow for a passage of gases to flow from the tubing 3and through the mask body 23. The pillows 24, 25 are preferably angledtoward one another and each have a preferably elliptical outlet 26, 27that may be slightly offset from the centre of each pillow 24, 25, asshown in FIG. 6.

FIGS. 18 and 19 a show a nasal pillow 24 with an offset outlet in moredetail. The pillow 24 has an outer profile 200 and inner profile 201with respective centre points 202, 203. The inner profile 201 (outlet ofthe nasal pillow 24) is offset inward, by a horizontal spacing 204 andvertical spacing 205. Meaning the outlet 201 of the nasal pillow isoffset horizontally 204 towards the middle of the nose and vertically205 towards the user's upper lip. Offsetting the outlet 201 downwards inthis manner allows the outlet to be inserted into a user's nostrilwithout the outer profile 200 pushing the user's upper lip. Offsettingthe outlet 201 inwards allows the pillow to better seal on the septum ofthe user's nose in use.

The outlet 201 may also be angled compared to the outer profile 200. Forexample in FIG. 18, there is a horizontal angle difference between theouter profile 200 and outlet 201 shown as 206. A similar vertical angledifference between the outer profile 200 and outlet 201 is shown as 207.

With the outer profile and inner profile having different sections oroffsets allows the gradient of the connecting surface between theprofiles to be changeable. This is shown in the graphs of FIGS. 19b, 19cand 19d . The connecting surface between the inner 201 and outer 200profiles can have differing gradients, 208, 209, 210. The differentgradients 208, 209, 210 of the connecting surface are possible due tothe difference in offset difference 211, 212 (horizontal, vertical orangled) between the inner 201 and outer 200 profiles.

There may also be a difference in the rate of change of the gradient (asillustrated in the difference between 208 and 210). This allows easierinsertion of the pillow 24 into a user's nostrils due to more lead inand better sealing that may be achieved due to more ergonomic contouringof the connecting surface that contacts the user's nostril.

Referring back to FIG. 7, the external lip 28 on the mask body 23 is anarea of reduced circumference around the tubular part of the body 23. Aprojection 47 may be provided on the lip 28 that fits with acorresponding recess or channel (discussed below) on the mask base 22 toensure correct assembly of the nasal mask.

The mask base 22 is shown in further detail in FIGS. 4 and 5. The maskbase 22 is a ring or sleeve type attachment. The base 22 is preferablymade from a substantially hard (rigid) plastics material, such aspolypropylene, polycarbonate or acetyl. However, other appropriatematerials may be used. The base 22 has an internal circumferentialrecessed area or channel 45 on one side and a semi-tubular projection 29on its other side. When assembling the mask body 23 to the mask base 22the channel 45 receives the lip 28. These parts are maintained togetherby friction fit, however other types of fitting may be provided for,such as a snap or bump fitted part or the body may be over moulded to aclip that causes the fitting to the mask body 23. In this form thefriction fitting of the lip 28 to the recessed area 45 is assisted byelongate projections 49 extending along the central part 50 of the maskbase 22. The projection 47 on the mask body 23 allows for correctfitting or keying of the mask base to the mask body, such that when thelip 28 is fitted into the recessed area 45, the projection 47 enters therecess 48 formed in the mask base 22.

The semi-tubular projection 29 is curved in this embodiment such that aball jointed connector end 46 such that a connector 30 can be fittedinto it. The projection 29 forms a socket for the connector end 46 andthe connector end can swivel within the socket. The connector 30 isattached to a tube 31 to allow for gases to be passed to the nasal mask2. The tubing 31 may be attached to inspiratory conduit 3 or the tubing31 may simply be the inspiratory conduit 3.

In alternative embodiments the projection 29 may not be semicircular butthe inner surface of the base 22 may be curved and form a socket forreceiving the connector end 46.

The base 22 has an extension or partial lip 32 extending beneath thesemi-tubular projection (socket) 29. A slot 33 is created between thesocket 29 and extension 32. The extension and slot is used to fit themask base 22 to the headgear 21. In this embodiment the extension 32 issubstantially curved to follow the shaped of the projection 29. However,in other forms the extension may be substantially straight or otherwiseshaped.

In use, the nasal mask is assembled with headgear 21. The headgear 21 inthe preferred form is comprised of headgear straps 35, 36, 37, 38 and asubstantially curved and elongate member 34. The member 34 is curved andsubstantially rigid, or at least more rigid than the headgear straps.

The headgear straps 35, 36, 37, 38 are preferably made from a compositefoam layered material, such as Breathoprene™. The headgear 21 preferablyincludes a first strap 35 and a second strap 36. The first strap 35extends in use over the forehead or top front area of a patient's head.The second strap 36 extends around the back of the patient's head. Theheadgear 21 also has side straps 37, 38 that in use extend down thechecks of a patient and the ends of the straps terminate in the upperlip area of the patient in use.

Referring to FIG. 2, the curved and elongate member 34 is comprised of acentral section 42 and contoured side arms 41, 54. A substantial lengthof each of the side arms 41, 54 overlaps and is attached to the sidestraps 37, 38. However, the side straps 37, 38 only extend partiallyalong the length of the side arms 41, 54 so as to terminate beneath thecheek or near the upper lip region. As the side straps 37, 38 are madefrom a soil foam type material they provide a comfortable fitting of theheadgear and curved member 34, while the substantially rigid side arms41, 54 provide rigidity and stability to the headgear 21 and nasal mask2. The attachment between the side straps and rigid extension side armsmay be made by gluing, sewing or other appropriate fastening.

Preferably the side arms of the curved member 34 are integrally mouldedwith the central section 42. The curved member 34 is preferably threedimensionally moulded to a shape to substantially match the cheekcontours of a human. The side arms 41, 54 are preferably of thinnerwidth (cross-section) than the central section 42. As the side arms 41,54 are moulded of a plastics material to be substantially thin they arecapable of being bent or adjusted to allow for better and morecomfortable fit to a patient. The side arms 41, 54 may also includeweakened or narrow areas 39 to allow for additional bending, moulding ortwisting of the arms 41, 54 to better fit the headgear to individualpatients. For example, in the embodiment shown in FIGS. 2 and 3, thenarrowed area 39 corresponds to the cheek bone area of a patient andallows for the side arms 41, 54 to easier bend or twist to fit thecontours of the patient's face.

In alternative embodiments the side arms may have weakened areas thatare narrower in cross-section to that of the remainder of the side arms.A narrower cross-section area would also provide a weakened area thatmay be easily manipulated.

In alternative embodiments of the present invention the side straps ofthe headgear may not extend under and along the length of the curvedmember but be attached to the distal ends of the straps. This attachmentmay be by hook and loop material, as is known in the art, or by otherattachment methods as known in the art. In this form, the arms of thecurved member may have padding underneath them or no padding at all.

Referring to FIG. 3, the curved elongate member has a central section 42that in an assembled form supports the mask base and body such that thepillows 24, 25 rest against the patient's nares. The central section 42is a half circle that is integrally moulded with the side arms 41, 54.The central section 42 has a raised area 43 on its exterior, at the apexof the half circle. The raised area 43 is shaped to receive the maskbase 22. To assemble, a patient merely needs to slide the mask base 22into the central section 42 such that the raised area 43 fits into theslot 33 on the mask base 22.

The side arms 41, 54 of the curved member 34 preferably have varyingcross-sectional thickness. The ends of the arms 41, 54 attached to thecentral section 42 are thicker over the most curved parts 55, 56 of thearms, whereas the straighter parts of the arms 57, 58 have a narrowcross-section. Therefore, the thicker ends 55, 56 hold their shapebetter.

In alternative embodiments, the mask base 22 may be formed integrallywith the curved member 34. Therefore, the central section and base wouldbe one and would not be able to be separated from one another.

An example of this is shown in FIGS. 20 to 22, the eighth embodiment ofthe patient interface and headgear 300. Here, the mask base 301 and thecurved elongate member 302 are integrally formed, for example, bymoulding or the like. The elongate member comprises arms 303, 304similar to that described above. Also the mask body 305 has integralnasal pillows 306, 307 similar to that described above in relation toFIG. 2.

As can be seen in FIGS. 21 and 22 in this eighth embodiment the headgearstraps 308, 309 do not extend down the arms 303, 304 as with otherembodiments. In this embodiment the headgear straps 308, 309 attachthrough recesses 310, 313 at the end of the arms 303, 304 extendingalong the arms are inner pads 311,312 that rest against the patient'scheekbones in use and provide comfort to the patient's face. The pads311, 312 only extend up to near the attachment recesses 309, 310. Thepads are preferably made from a foam type material, such as thelaminated material that the headgear straps are made from. The pads 311,312 preferably do not extend beyond the edges of the arms 303,304.

Referring back to FIGS. 2 and 3, alternatively, the curved member 34 maybe formed as two separate pieces. That is, the central section 42 may beformed as two parts with a central split seam, the two left and righthalves joined in use. The two left and right parts could either bejoined along a seam as described above, with the base 22 slotting intothe slot 33 as described above, or alternatively, each of the two leftand right arms may be attached one to each side of the base 22.

Where a “substantially continuous elongate member” or “curved member” isreferred to in this specification, it refers to any of the options forthe curved member 34 outlined above.

The side arms 41, 54 may also include a loop 40 or detached section.This is where a section of the side arms 41 is not attached to the strap38, 37 lying underneath. Thus the detached section 40 of the side armsforms a loop to which a tubing attachment 44 (such as that shownattached to another strap in FIGS. 2 and 3) may be looped to the sidearms 41, 54 and the tubing 31 attached to either of the side arms.

The connector 30 in the preferred form is a ball and socket jointedconnector to allow for the tubing 31 to swivel in the mask base 22. Thetubing 31 may be attached to any of the headgear straps. However, a tubeattachment 44 is shown where the tubing is attached by fasteners, suchas hook and loop fastener, to the first strap 35. In other embodimentsthe tubing 31 may be attached to either the side straps 37, 38 or merelyallowed to fall freely from the nasal mask 2.

Although a ball and socket joint, as described above, between the maskbase 22 and tubing 31 is preferred other connections may be utilised,such as a flexible piece of silicone, or other appropriate connection.The connection between the base and tubing must be able to be flexed orrotated to allow for the tubing to be moved without causing thedislodgement of the nasal mask 2 from the user's nares.

The mask body 23 may be provided with nasal pillows of various differentsizes, such that user's may remove an existing mask body and simplyattach a different sized body to the mask base 22.

Alternative headgear may be used with the patient interface of thepresent invention. In particular, alternative headgear is shown in usewith the first form of the patient interface (of FIG. 2) in FIG. 8. Herethe headgear may include an additional strap 53 extending from the cheekregion of the side straps 41 and extending behind the user's head. Thislower additional strap 53 may also include substantially rigid arms 51similar to the arms 41 described above. Any number of connecting straps52 may also be provided between the upper strap 36 and lower strap 53.Again, the arms 51 would provide stability and rigidity to theadditional strap 53.

In the embodiment described above, when the patient interface of thefirst form is in use, the user's face causes the mask base 22 and body23 to clip with the curved member 34. This is due to the angle of thecurved member 34 and fixing of the mask base 22 and body 23 to thecurved member 34.

Further, in all forms, the curved member 34 transfers the load of thepatient interface away from the user's nose and to the cheek regions ofthe user.

A second form of the patient interface and headgear of the presentinvention is shown in FIGS. 9 and 10. In this embodiment a mouthpiece100 is attached to the substantially tubular mask body 23 substantiallybelow the nasal pillows 24, 25. The mouthpiece 100 is preferably a flapthat is fittable within the patient's mouth. A gases pathway extendsthrough the mask body 23 and through the centre of the mouthpiece 100,such that in use a patient or user is supplied with gases via the nasalpillows 24, 25 and the mouthpiece 100. The flap 100 is preferably madefrom a silicone plastics material but other appropriate materials suchas rubber, thermoset elastomer or thermoplastic elastomer, such asKraton™ may be used. The flap 100 is preferably integrally moulded withthe mask body 23 and nasal pillows 24, 25. In use the flap 100 sitswithin the user's mouth between the user's teeth and lips.

In this second form the headgear and particularly the curved member 34is substantially the same as that described in relation to the firstembodiment.

A third form of the patient interface and headgear of the presentinvention is shown in FIG. 11. In this embodiment a mouthpiece as wellas a nose blocking device is attachable to the mask base 22. Themouthpiece 110 and nose blocking device 111 are preferably integrallyformed. The mouthpiece 110 has an inner vestibular shield 112 that issimilar to the flap 100 described above. Therefore the vestibular shield112 in use sits within the patient's mouth between the patient's teethand lips and provides an at least partial seal between the user and theshield 112.

A tubular extension 113 extends through the mouthpiece 110 to the maskbase 22 from the vestibular shield 112. The extension allows for gasesto be passed to the patient from the conduit 31.

The nose blocking device 111 in use rests under the user's nose andblocks the user's nares.

In this third form the headgear and particularly the curved member 34 issubstantially the same as that described in relation to the firstembodiment.

A fourth embodiment of the patient interface and headgear of the presentinvention is shown in FIG. 12. In this embodiment a mouthpiece 120, 121is attachable via a tubular extension 122 to the mask base 22. Themouthpiece is made up of an outer mouthpiece flap 120 and an innervestibular shield 121. The shield 121 is substantially the same as thatdescribed in reference to the third embodiment. The outer mouthpieceflap 120 rests in use outside the user's mouth and substantially sealsabout the user's mouth. The outer mouthpiece flap 120 and an innervestibular shield 121 are described in further detail in U.S. Pat. No.6,679,257, the entire contents of which is herein incorporated byreference.

In the fourth form of the headgear and particularly the curved member 34is substantially the same as that described in relation to the firstembodiment.

A fifth form of the patient interface and headgear of the presentinvention is shown in FIGS. 13 and 14. This embodiment is very similarto the fourth embodiment except the mouthpiece is simply an outermouthpiece flap 130. This flap 130 is liftable to the mask base 22 byway of the tubular extension 131. Again, as above, the headgear andparticularly the curved member 34 are substantially the same as thatdescribed in relation to the first embodiment.

A sixth form of the patient interface and headgear of the presentinvention is shown in FIG. 15. In this embodiment the patient interfaceis a full face mask 140 that extends over a user's nose and mouth andunder the user's chin in use. The mask 140 has a body 142 made from asubstantially rigid plastics material and a cushion 144 made from asubstantially soft plastics material. The mask and cushion arepreferably similar to that described in more detail in U.S. patentapplication Ser. No. 11/368,004, the entire contents of which isincorporated herein by reference.

A tubular inlet port 143 is formed in the mask body 142. The tubing 31is attachable to the port 143 to provide gases to the user wearing themask.

The headgear is substantially similar to that described in relation toFIG. 2 (the second form); however, the curved member 141 differs. Thecurved member 141 does not have a mask base similar to that described inthe second form in which to attach to. Therefore, the curved member 141has a central section 145 that curves under the inlet port 143,effectively anchoring on the inlet port. The curved member 141 ismoulded in substantially the same manner as described with reference tothe second form.

A seventh form of the patient interface and headgear of the presentinvention is shown in FIGS. 16 and 17. Here, the headgear and curvedmember is similar to that described above in the sixth embodiment, wherethe curved member 141 has a central section that curves under andanchors onto an inlet port 151 on a patient interface 150. The patientinterface 150 is an integral mouth mask 152 and nasal pillows 153. Themouth mask 152 preferably extends under the user's 155 chin, as shown inFIG. 17.

The interface 150 has a substantially rigid body 154 that hassubstantially soft cushion 156 attached to it. The cushion 156 ispreferably of the type disclosed in U.S. Pat. No. 6,951,218 (the entirecontents of which is incorporated herein by reference) having an inner157 and outer 158 cushions.

Integrally formed in the outer cushion 158 are nasal pillows 153.Preferably two nasal pillows 159, 160 are formed in the cushion 158.These are substantially tubular and carry gases in use from the insideof the interface 150 to the user's 155 flares. The outer cushion 158 andnasal pillows 159, 160 are preferably made from a soft pliable plasticsmaterial such as silicone but other appropriate materials such as rubberor KRATON™ may be used.

A similar but slightly different embodiment to that of FIG. 16 is aninth embodiment of the present invention, as shown in FIG. 23. Here theinterface 400 is substantially the same as the interface 150 of FIGS. 16and 17. The interface 400 has a body 401 with integral nasal pillows402, 403. The nasal pillows may be integrally formed with the body orseparately formed and simply assembled to the body before use. The nasalpillows 402, 403, as above, are substantially tubular and carry gases inuse from the inside of the interface 400 to the user's mires. Again,nasal pillows are preferably made from a soft pliable plastics materialsuch as silicone but other appropriate materials such as rubber orKRATON™ may be used.

In this embodiment the body 401 may be made of a more rigid materialthan the nasal pillows or simply be made from a soft pliable plasticsmaterial as are the nasal pillows.

Attached to an inlet 404 of the body 401 is an elongate member 405similar to that described in any of the embodiments detailed above, butparticularly that of FIGS. 20 to 22. The elongate member 405 has arms406, 407 that extend along a user's cheekbones then up towards theuser's ears when in use. The arms 406, 407 are preferably made from asubstantially rigid material, preferably a plastics material. For theusers comfort each of the arms 406, 407 have inner pads (only one pad408 is shown in FIG. 23) extending along their inner sides, particularlywhere the arms are incident on the user's face.

The arms 406, 407 have recesses 409, 410 at the ends to which headgearstraps 411, 412 are attached. The arms 406, 407 may also each haveoptional side hooks (of which only one side hook 413 is shown), againmade out of a substantially rigid material, to which additional sideheadgear straps 414, 415 may be attached.

At the centre of the elongate member 405 is formed an integral inlet 416that matches and attaches to the inlet 404 on the body. This integralinlet 416 receives a conduit or tube 417 that is connected in use to asupply of gases. Preferably the tube 417 has a swivelable elbow 418 (forexample, a ball joint socket similar to the one described above).Preferably on the elbow 418 are a number of holes 419 that provide anexhaust vent for gases exhaled by the patient in use.

In this ninth embodiment of the patient interface and headgear theinterface is a mouth mask and nasal pillows. In alternative forms thepatient interface may be a full face mask that is attached to anelongate member and headgear similar in form to those described aboveand particularly in relation to FIG. 23.

What is claimed is:
 1. A mask assembly for supplying breathing gases toa user, the mask assembly comprising: a body portion comprising an inletportion disposed on a distal end of the body portion, first and secondnasal pillows disposed on a proximal end of the body portion and acentral portion disposed between the proximal and distal ends, the firstand second nasal pillows being adapted to rest in a substantially sealedmanner against a user's nares in use, the inlet portion of the bodyportion comprising an outer circumferential surface, a reducedcircumference lip extending distally away from the central portion, anda stepped wall comprising a transverse face disposed between andextending transverse to the outer circumferential surface and thereduced circumference lip, the reduced circumference lip comprising areduced circumference outer surface and a distal end face on a distalend of the reduced circumference lip and extending transverse to thereduced circumference outer surface; and a base portion comprising abody portion connector and an inlet, the body portion connector beingdisposed on a proximal side of the base portion and facing toward thedistal end of the body portion, the body portion connector comprising acircumferentially extending channel facing toward the distal end of thebody portion, the circumferentially extending channel comprising aninner wall and an outer wall, the outer wall comprising an outer wallend face on a proximal end of the outer wall, the outer wall end faceextending transverse to the circumferentially extending channel; whereinthe base portion is connected to the body portion with the reducedcircumference lip disposed in the circumferentially extending channel,between the inner and outer walls of the circumferentially extendingchannel, the outer wall end face of the outer wall being juxtaposed tothe transverse face of the stepped wall, and wherein the reducedcircumference outer surface is juxtaposed to an inner surface of theouter wall of the circumferentially extending channel.
 2. The maskassembly of claim 1, wherein the body portion and the base portion areconnected together with one of a bump fit and a snap fit.
 3. The maskassembly of claim 1, wherein the base portion comprises elongateprojections extending on the inner wall of the circumferentiallyextending channel.
 4. The mask assembly of claim 3, wherein the elongateprojections are configured to assist the fitting of the reducedcircumference lip to the circumferentially extending channel.
 5. Themask assembly of claim 4, wherein the body portion is overmoulded to aclip, the clip fitting the body portion to the base portion.
 6. A maskassembly for supplying breathing gases to a user, the mask assemblycomprising: a body portion comprising an inlet portion disposed on adistal end of the body portion, first and second nasal pillows disposedon a proximal end of the body portion and a central portion disposedbetween the proximal and distal ends, the first and second nasal pillowsbeing adapted to rest in a substantially sealed manner against a user'snares in use, the inlet portion of the body portion comprising an outercircumferential surface, a reduced circumference lip extending distallyaway from the central portion, and a transverse face connecting theouter circumferential surface and the reduced circumference lip; and abase portion comprising a body portion connector and an inlet, the bodyportion connector being disposed on a proximal side of the base portionand facing toward the distal end of the body portion, the body portionconnector comprising a channel facing toward the distal end of the bodyportion; wherein the base portion is connected to the body portion withthe reduced circumference lip being disposed in the channel and thetransverse face juxtaposed to a proximal portion of an outer wall of thechannel.
 7. The mask assembly of claim 6, wherein the reducedcircumference lip extends circumferentially around a distal side of thebody portion and wherein the reduced circumference lip is connected tothe channel.
 8. The mask assembly of claim 6, wherein the outercircumferential surface has a greater circumference than an outercircumference of the reduced circumference lip such that the reducedcircumference lip defines an area of reduced circumference around adistal side of the body portion relative to the outer circumferentialsurface.
 9. The mask assembly of claim 6, wherein the base portioncomprises at least one elongate projection extending on an inner wall ofthe channel.
 10. The mask assembly of claim 9, wherein the at least oneelongate projection is configured to assist the fitting of the reducedcircumference lip to the channel.
 11. The mask assembly of claim 10,wherein the body portion is overmoulded to a clip, the clip fitting thebody portion to the base portion.
 12. A mask assembly for supplyingbreathing gases to a user, the mask assembly comprising: a base portionand a body portion; the body portion comprising a first nasal pillow anda second nasal pillow, the first and second nasal pillows adapted torest in a substantially sealed manner against a user's nares in use, thebody portion also comprising a lip extending from a distal side of thebody portion, the lip defining an area of reduced circumference aroundthe distal side of the body portion, and wherein the body portion alsocomprises a stepped transition transitioning the distal side of the bodyportion to the area of reduced circumference; the base portioncomprising a channel configured to receive a portion of the lip when thebase portion is connected to the body portion.
 13. The mask assembly ofclaim 12, wherein the lip extends circumferentially around the distalside of the body portion.
 14. The mask assembly of claim 12, wherein thestepped transition forms an abutment face that abuts an outer wall ofthe channel.
 15. The mask assembly of claim 14, wherein the channelextends around a circumference of the base portion.
 16. The maskassembly of claim 12, wherein the lip is connected to the channel. 17.The mask assembly of claim 12, wherein the base portion comprises atleast one elongate projection extending on an inner wall of the channel.18. The mask assembly of claim 17, wherein the at least one elongateprojection is configured to assist the fitting of the lip into thechannel.
 19. The mask assembly of claim 18, wherein the body portioncomprises a substantially flexible material and the base portioncomprises a substantially hard material.
 20. The mask assembly of claim19, wherein the body portion is overmoulded to a clip, the clip fittingthe body portion to the base portion.